Assig-nob to the hydeaulic



(No Model.)

W. E. HALE.

AEMMEN() ENGINE. No. 959,999.V Patentd Feb. 1., 1987.

` UNITED STATES PATENT OFFICE.v

WILLIAM'E. HALE, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE HYDRAULIC ELEVATOR COMPANY, OF SAME PLACE.

. HYDRAULIC ENGINE.

SPECIFICATION forming part of Letters Patent No. 356.999, dated February 1l 1887. Application tiled January 10, 1884. Serial No. 117.081. (No model.) A

To aZZ whom it may concern:

Be it known that I, WILLIAM E. HALE', of Chicago, Cook county, Illinois, have invented certain Improyements in Hydraulic Engines, of which the following is the specification.

My invention relates to that class of waterengines usually employed for elevators, in which the piston is moved in one direction by the pressure of Water from a supply-reservoir and in the other direction by the weight of the load while the water circulates from end to end of the cylinder; andmy invention consists in means, fully described hereinafter, whereby to permit a ready circulation of the Water when all connection with the supply is cut off.

In the drawings, Figure 1 is an elevation in part-section, showing my invention as applied to a hydraulic enginehaving a horizontal cyl- Inder. Fig. 2 is a sectional elevation of a vertical-cylinder engine embodying my invention. Fig. 3 is a sectional elevation of a vertical cyl- Inder-engine receiving the Inotorluid atv the opposite end from that shown iii Fig. 2.

In hydraulic engines used for elevators it is common to circulate the Water from one side ofthe piston to the other as the piston is moved either out or in, according to the structure, by the weight of theload, the circulating-channel, either in the cylinder or exterior circulationpipes, being in communication with the motoriiuid under pressure. This communication in the described engines is essential, as the piston-rod on one side of the piston contracts the water-space rat-such side, so' that the water inl the larger space on the opposite side cannot be transferred, while the water from the pistonrod side will not fill the opposite space, and a partial vacuum would result upon any transfer. The communication with the source of supply affords opportunity for the escape of water from one side of the piston and supplies the deficiencyif the circulation isintheopposite direction. y

To avoid the necessity of maintaining the vwat-er in the cylinder under constant pressure from the source and yet permit a free circula-` tion, I construct the valve device, of any suitable kind, so as to close the supply-pipe when the piston is moving under the load and the water is circulating; and I also provide a communication between the water-circulating passage and a separate open tank, so that the water required'to supply the deficiency, or which is in excess, may pass freely between the tank and the cylinder.

When the cylinder is horizontal, as shown in Fig. 1, and the water` from the supply-pipe A acts upon the outer or piston-rod side of the .piston B to force it to the opposite or. inner end, S, of the cylinder C, the communication is made with lthe tank T (which may loe the usualdischarge-tank) through a pipe, a, communicating with the end of the cylinder Vfroml which,v the water is discharged when the load is lifted. Thispipe a dips below the water in the tank, and the Water will have a free passage tothe cylinder when there is any deliwhen the valve D is in the position shown in Fig. l and the water is circulating from the volume in front of the piston diminished by the displacement of the piston-rod being insulicient to supply the space at the rear. der these conditions the water will be drawn and will rise freely from the tank in to the cylinder.

In Fig. 2 the invention is illustrated in connection with avertical-cylinder machine, where the Weight of the load d epresses the piston and the pressure of waterfrom the supply-pipe A lifts it. In this case the pipe a extends to and communicates With the upper or discharge end of the cylinder, and when the water circulates, on the descent of the piston, through the pipes below the cylinder to pass to the tank.

structed to lift the load under pressure on the top of the piston, the load' lifting the piston. In this case, also, the dischargeend of the cylinder communicates with the tank through the pipe a, and the tank supplies the deiiciency when the water-from above passes below the piston as the load lifts the latter.

In each case there is a free communication betweenthe water-tank and the cylinder, and the water to supply any deciency within the cylinder or any surplus therefrom passes automatically from or to the cylinder without the ciency within the cylinder-as, for instance,

"forward to the rear end of the Vcylinder-the G H and valve-case I, permits the excess from In Fig. 3 the`vertical-cylinder engineis con- IOO control of any cocks or valve appliances,with out any manipulation by the attendant, and without the necessity of providing any remedy against the undue escape of water from the supply source.

It is dicult to pack the piston and pistonl'odof a vertical-cylinder engine so that air will not pass into the upper end of the cylinder and water dow downward past the piston when the engine is at rest if the lower end be open, as is the case when the pipe a communicates with said end.

To prevent the escape 0f the water and the admission of air under suchV circumstances, I provide the lower end of the pipe a with a cl1eclr-valve, e, as shown in Fig. 3, which closes under the weight of the column above and prevents any downward discharge. While this valve closes the pipe when the engine is at rest, there is no obstruction of the pipe when the Water is in circulation, and that in the tank rises to supply the deciency in the cylinder, the valve being only a safety adjunct to prevent loss when the engine is at rest if leakage should occur, and having no effect so far as the circulation is concerned.

I claim- 1. The combination, with the cylinder' and supply, circulating, and discharge pipes, and valve of a hydraulic engine, of awater tank and pipe to afford an independent communication hetween the discharge end of the cylinder and the tank, substantially as and for the purpose described.

2. The combination, with a hydraulic en gine havingsupply, circulating, and discharge pipes, of a pipe independent of said pipes and extending from the discharge end of the cylinder and alfording a free communication between the same and a tank, substantially as and for the purpose set forth.

3. The combination, iu a hydraulic engine, of a cylinder, and supply, circulating, and discharge pipes, and valve, and a pipe independent of said` supply, circulating, and discharging pipes and extending from the discharge end of the cylinder to an open tank, as and for the purpose set forth.

4. The combination, with the working cylinder, and supply, circulating, and discharge pipes,of a supply-tank communicating with the cylinder through a passage independent of said pipes, provided with a valve arranged to open automatically to admit water freel y to the cyl inder, substantially as described.

5. In a hydraulic elevator, a cylinder containing the working-piston,and provided with supply, discharge, and circulating pipes in communication with awatertank through a passage independent ot said pipes, provided with a valve arranged to close under pressure from within rthe cylinder, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

WILLIAM E. IIA LE. Vitnesses:

CHARLES, E. Fosrnn, F. L. FREEMAN. 

